82 turbo seca help

Howdy yall!

Just picked up this bike last week, it ran but would only hit around 7500 RPM. and only idles at around 2000rpm, otherwise it will randomly die sitting there.

Turbocharger was rebuilt by a shop a few years ago.

After going through the vac lines, (it has a replaced petcock, with a prime, res, on) because it would only run on prime. It will barely start now.

What i changed was, had the surge tank running to the boost sensor, so i switched it back to the fuel pressure reg, which is aftermarket. And than ran the boost sensor to the rubber boots after the carb. I see now after this it should be running to the venturi portion of the carbs which i will swap back. (have that running to the petcock but it runs on the on now! even though it wont work under boost...)

However it will only start after purging the fuel lines, and i can see air in the fuel lines and wondering how to go on next...

Also where is this 10mm nut on the turbo to open the waste gate? i see people say it is on top but i am unable to find it.

Will post photos when i get home

 

Do you have the Yamaha supplemental manual for the Turbo?

 

I have the manuals that i can find online in this forums,
The big long one that you can google that was made my the forums members

this one has been a massive help, but this is the first time im diving into a "project bike" my other bike is an 84 magna, but it hasnt needed any work

The reason i am trying to find this bolt on the turbo, is that i revved the engine to 5k and did not feel any exhaust pressure exiting the right exhaust.

 

Not sure what bolt you’re looking for but you won’t see anything coming out of the RH pipe until the wastegate opens, on mine probably happens around 8,000 rpm

 

There is a Yamaha manual for the Turbo

 

Yep i found one that is only about 4 pages long.

Been helpful understanding the system, but would you know how one would effectively tune a aftermarket pressure regulator?

seems that it had to go over a curve. assume just have to hook up a fuel gauge to the fairings and let her eat on the highway

 

You do not have the manual.
The Yamaha Turbo supplement has to be 100 pages.
I can't contemplate working on one of these without it.
Let me see if I have it electronically once I get home today.

Typically the aftermarket FPR's have an adjustment bolt with a lock nut.
Most for the auto world are too high pressure but some go as low as 4-1/2 psi.
You need to be 2.8 psi
I know some have them installed with good results.
I would suspect too high a fuel pressure would cause a rich condition.

 

Thank you for the help.
Yes, current one is a Holley 12-887, 4.5-9 psi.


I thought the fuel pressure was increased to around 7 once boost was reached? I was going to put on an OEM one but i was unable to find one anywhere, along with an OEM petcock, because i prefer having a reserve switch

Also it doesnt have a return line back to the tank on this petcock...

 

@Simmy, is the fuel pressure not supposed to be 2.8 psi above the boost pressure? Or am I remembering that wrong? No, I don't have any documentation to that effect, just a vague rememberance ......

 

yes the OEM FPR maintains 2.8 psi above boost.
So if you boost to 11 psi your float bowls will be 13.8

 

howdy!!

I have the fuel set to around 3 - 3. 5 off of the FPR,

Cheap harbor freight gauge but it seems the lowest it will go.

However as the bike runs and idles i noticed the tube flowing from the petcock on down barely allowing any fuel past. and than starts running rough (about a milimeter deep)

Took apart the petcock on the tank and it seems to be free, yet to remove it to check to see if the filter or something is plugged

 

Here are some pictures of the fuel system as sits

https://imgur.com/gallery/82-seca-iVpvSg2


Fuel runs from petcock to a T

One side goes to the FPR- which follows on to the left side of the check valve.

The other side of the T runs to the fuel pump, than another petcock (red one) and the right side of the CV.


as it idles the petcock line will basically drain out, and a bunch of air is visibile when it is running in the lines

 

OK sounds like you have a deadhead style FPR. The OEM is a by-pass type which requires a return line to the tank.
This will require a different configuration from the OEM set up.

I see you have an aftermarket pump also, shouldn't matter much except the amperage, there is not a lot to spare with the XJ's charging system.

I found the Yamaha turbo manual in pdf 135 pages Canadian by-lingual version
If you set up a file sharing account you can invite me to drop a file there.
I'll PM you my email

 

Thank you very much!! if you have any recommondations for a different fuel pump im more than open!